Variability and spectral classification of LMC giants: results from DENIS and EROS

Abstract

We present the first cross-identifications of sources in the near-infrared DENIS survey and in the micro-lensing EROS survey in a field of about 0.5 square degrees around the optical center (OC) of the Large Magellanic Cloud. We analyze the photometric history of these stars in the EROS data base and obtain light-curves for about 800 variables. Most of the stars are long period variables (Miras and Semi-Regulars), a few Cepheids are also present. We also present new spectroscopic data on 126 asymptotic giant branch stars in the OC field, 30 previously known and 96 newly discovered by the DENIS survey. The visible spectra are used to assign a carbon- (C-) or oxygen-rich (O-rich) nature to the observed stars on the basis of the presence of molecular bands of TiO, VO, CN, C2. For the remaining of the stars we used the (J-Ks) color to determine whether they are O-rich or C-rich. Plotting Log(period) versus Ks we find three very distinct period-luminosity relations, mainly populated by Semi-Regular of type a (SRa), b (SRb) and Mira variables. Carbon-rich stars occupy mostly the upper part of these relations. We find that 65% of the asymptotic giant branch population are long period variables (LPVs).

9 pages, 7 figures, 4 tables (2 via CDS), accepted by A&A journal

References in corpus (4)

• The DENIS Point Source Catalogue towards the Magellanic Clouds
• Obscured AGB stars in the Magellanic Clouds II. Near-infrared and mid-infrared counterparts
• Hipparcos period-luminosity relations for Miras and semiregular variables
• MACHO Project Photometry of RR Lyrae Stars in the Sgr Dwarf Galaxy

Cited by in corpus (57)

• AGB Variables and the Mira Period-Luminosity Relation
• The global gas and dust budget of the Large Magellanic Cloud: AGB stars and supernovae, and the impact on the ISM evolution
• Variable Stars in the Magellanic Clouds: Results from OGLE and SIRIUS
• The distance to the giant elliptical galaxy NGC 5128
• Reprocessing the Hipparcos data for evolved stars III Revised Hipparcos period-luminosity relationship for galactic long-period variable stars
• AGB stars in the Magellanic Clouds. II. The rate of star formation across the LMC
• The metallicity gradient as a tracer of history and structure: the Magellanic Clouds and M33 galaxies
• A Spitzer mid-infrared spectral survey of mass-losing carbon stars in the Large Magellanic Cloud
• Red variables in the OGLE-II database. I. Pulsations and period-luminosity relations below the tip of the Red Giant Branch of the LMC
• AGB stars in the Magellanic Clouds. I. The C/M ratio
• Spitzer Space Telescope spectra of post-AGB stars in the Large Magellanic Cloud ---polycyclic aromatic hydrocarbons at low metallicities
• The red tail of carbon stars in the LMC: Models meet 2MASS and DENIS observations
• New Optical and Near-Infrared Surface Brightness Fluctuations Models. II. Young and Intermediate Age Stellar Populations
• The Modelling of Intermediate Age Stellar Populations. II. Average spectra for upper AGB stars, and their use
• Variable stars in the Magellanic Clouds: II. The data and infrared properties
• Dust-driven Winds and Mass Loss of C-rich AGB Stars with subsolar Metallicities
• A Near-Infrared Period-Luminosity Relation for Miras in NGC 4258, an Anchor for a New Distance Ladder
• Long Period Variables in the Magellanic Clouds: OGLE + 2MASS + DENIS
• Infrared Photometry and Evolution of Mass-Losing AGB Stars I. Carbon Stars Revisited
• Shock processing of interstellar dust and polycyclic aromatic hydrocarbons in the supernova remnant N132D
• Long Period Variables in the LMC: Results from MACHO and 2MASS
• Long Period Variables detected by ISO in the SMC
• The global gas and dust budget of the Small Magellanic Cloud
• Spitzer Space Telescope spectral observations of AGB stars in the Fornax dwarf spheroidal galaxy
• Red variables in the OGLE-II database. II. Comparison of the Large and Small Magellanic Clouds
• Joint Analysis of near-infrared properties and surface brightness fluctuations of LMC star clusters
• Non-adiabatic Oscillations of Red Giants
• The VMC Survey -- XXXIV. Morphology of Stellar Populations in the Magellanic Clouds
• AGB stars as tracers of metallicity and mean age across M33
• Interstellar Extinction and Long-Period Variables in the Galactic Center
• Carbon stars as standard candles: I. The luminosity function of carbon stars in the Magellanic Clouds
• Red variables in the OGLE-II data base -- III. Constraints on the three-dimensional structures of the LMC and SMC
• The First Fluorine Abundance Determinations in Extragalactic AGB Carbon Stars
• Stellar substructures in the periphery of the Magellanic Clouds with the VISTA Hemisphere Survey from the red clump and other tracers
• Long Period Variables in NGC 5128: II. Near-IR properties
• Extreme Infrared Variables from UKIDSS - I. A Concentration in Star Forming Regions
• Fast X-ray transients in the Galactic bulge with the Rossi X-ray Timing Explorer
• Age Gradients Throughout the Galaxy with O-Miras
• Observation of periodic variable stars towards the galactic spiral arms by EROS II
• Carbon stars as standard candles: II. The median J magnitude as a distance indicator
• On the pulsation modes of OGLE small amplitude red giant variables in the LMC
• Mid Infrared Photometry of Mass-Losing AGB Stars
• Properties of self-excited pulsations in 3D simulations of AGB stars and red supergiants
• VLBI Astrometry of the Semiregular Variable RX Bootis
• Period-magnitude relations for M giants in Baade's Window NGC6522
• M giants in Macho, DENIS and Isogal
• Late-type giant variables in NGC6522, LMC and SMC: How do they differ?
• Long-period variables in NGC147 and NGC185
• A Remarkable Oxygen-rich Asymptotic Giant Branch Variable in the Sagittarius Dwarf Irregular Galaxy
• Pulsation properties of C stars in the Small Magellanic Cloud
• Limits on I-band microvariability of the Galactic Bulge Miras
• A Distance Measurement to M33 Using Optical Photometry of Mira Variables
• Oxygen- and carbon-rich variable red giant populations in the Magellanic Clouds from EROS, OGLE, MACHO, and 2MASS photometry
• Difference of photometric properties between regular and non-regular Miras in the Magellanic Clouds
• Emission-line stars in M31 from the SPLASH and PHAT surveys
• Three aspects of red giant studies in the Magellanic Clouds
• Photometric Properties of Long-period Variables in the Large Magellanic Cloud